More than a century ago, Chicago used a combination of grit, muscle and money to turn around the Chicago River. That move forged an important connection between the Great Lake Michigan and the mighty Mississippi. It was an incredible act of engineering and created a back door to the Great Lakes, but also had some unintended consequences.

If the Chicago River is the back door of Lake Michigan, then the St. Lawrence Seaway is the front door, a water superhighway for big cargo ships. It stretches more than 2,000 miles from Lake Ontario to the Atlantic Ocean. Construction of the route in the 1950s transformed the economy and the ecology of the Great Lakes.

Beginning Monday, June 20, Front and Center will be exploring the front and back doors of the Great Lakes: the St. Lawrence Seaway and the Mississippi River. We are sending reporters down each river, follow their journey online and onair.